Ken, that is a very good point (about battery mounts). I don't trust them anymore. I use black tape and call it good, even on the most aggressive of boosts...

I have allways taped them in. 200 mph 😳 I mean 1000 mph Duct Tape. I didnt want to learn the hard way.

I think I figured out why my drogue descent rate was 180fps - I was looking over the data, and the charges weren't nearly as energetic as normal. My apogee separation was somewhat delayed, and only reached a peak of 11G at separation. For comparison, on my last flight, it reached in excess of 50G at charge ignition, and reached it almost instantly. I'm somewhat wondering if my charge burned slowly/incompletely due to the high altitude - that's the highest I've gone by a solid mile or so, and air pressure is only 40% of sea level or so.

So how did a delayed drogue separation result in higher descent rate?
At BALLS my sustainer and 2nd stage fell at 96 and 120 ft/second, respectively, during their drogueless descents (with full motor weight, sadly)

I assume the $85 was just for the transmitter right? Do you guys use them in the cases? Can you reposition the antenna? I'm trying to figure out how small a rocket diameter it would fit in.

Oh, and anyone know the difference between the dc20 and the dc30?

I assume the $85 was just for the transmitter right? Do you guys use them in the cases? Can you reposition the antenna? I'm trying to figure out how small a rocket diameter it would fit in.

I have both.
38mm for the dc20 if you move the antena
dc30 could be smaller but I chickened out taking it apart.
Its more expensive you know.

I think I figured out why my drogue descent rate was 180fps - I was looking over the data, and the charges weren't nearly as energetic as normal. My apogee separation was somewhat delayed, and only reached a peak of 11G at separation. For comparison, on my last flight, it reached in excess of 50G at charge ignition, and reached it almost instantly. I'm somewhat wondering if my charge burned slowly/incompletely due to the high altitude - that's the highest I've gone by a solid mile or so, and air pressure is only 40% of sea level or so.

So how did a delayed drogue separation result in higher descent rate?
At BALLS my sustainer and 2nd stage fell at 96 and 120 ft/second, respectively, during their drogueless descents (with full motor weight, sadly)

Delayed wasn't the issue - if the drogue didn't come out fully, or was slightly tangled, 180fps is completely believable. I had a 4" by 7' rocket with a 30lb recovery weight - it's quite a bit more dense than most rockets. I'm wondering if the delayed and less energetic spike indicates that the charge didn't burn fully, allowing only a partial drogue deployment. I don't have any solid proof of what happened (nobody saw it at all after apogee), but it would make sense. It would also explain some odd changes in the data at around 2000 feet.

I got my DC20 (in the orange case) in a 2.5" coupler in my rocket. I didn't like taking it apart since it was in such a good weather and waterproof housing.

Edward

Do either of the dog collars tell the max altude?, (within 5 seconds, according to garmin)?

Seems to be the most fail safe way to find my rocket, incase i blink.

Daivd

You can see the altitude after you get it back and download the track from the collar. You cannot see it live. Though you can see how fast it is traveling (horizontally) live.

Edward

A live speed feed that's pretty cool. At ◦4.1 oz (116 g) for transmitter and antenna. Perhaps dual deploy is the finesse route, could still have a long flying drogue. How fast is to fast for falling second deployment? Ballistic to 1000' does not seem like a safe idea, could just be my inexperience.

Thanks

David

Edward & Batman, I've been able to take my DC20 case off, zip tie the battery to the unit and rotate the antenna 90* pointing up into a nose cone. It will fit inside a 38mm MD rocket nose cone with room to spare.

You have to be very careful when moving the antenna mount or you will break off the wire and have to send it back like Mike did. He was able to find a 90* fitting so he didn't have to move the mount from its stock position. I would do it this way next time too.

Testing. I set the stock orange box DC20 3' away from my nose cone laying on it's side (on the ground) and started driving off into the hills in KS. I had maybe 100 yds of difference in the tacking distance. Hills were enough that line of sight was nil, I got 2.5 miles of range consistently. When I drove up the road on flat ground I could get 4+ miles of range.

oops, forgot the pics.

Charging the unit - I cut off the end of the orange box with the connections and wires on it....

Does anyone know what frequency the collars transmit on?

I don't have it on me, but the manual for the Astro 220 at Garmin's site has a table of all the frequencies & channels.

-Ken

Found it thanks